AB0779 NAILFOLD VIDEOCAPILLAROSCOPY IN ANCA-ASSOCIATED VASCULITIS
Authors: M. Sullivan, N. Aslam, A. Abril, C. Ball, F. Berianu
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Nailfold videocapillaroscopy (NVC) is a simple and noninvasive tool utilized by rheumatologists for monitoring of systemic sclerosis, dermatomyositis, and Raynaud's phenomenon [1]. A capillaroscope is utilized to view the nailfold capillaries and evaluate for evidence of small vessel abnormalities, which can be seen with the aforementioned disorders. Other forms of rheumatologic disease such as ANCA-associated vasculitis (AAV) are already known to cause capillaritis. This is the proposed mechanism for some of the disease manifestations including pulmonary alveolar hemorrhage and glomerulonephritis(2, 3). We sought to clarify whether patients with AAV would have corresponding abnormalities on NVC. <h3>Objectives:</h3> 1.Characterize NVC characteristics in patients with AAV. 2.Define the prevalence of dilated capillaries, microhemorrhages, ramifications, disorganization, and decreased density in patients with AAV compared to controls. <h3>Methods</h3> Patients over the age of 18 with a diagnosis of small vessel vasculitis based on Chapel Hill Criteria or confirmed on biopsy were identified for inclusion in the trial and invited to participate. Patients with co-existing disorders that are felt to impact NVC results were excluded: dialysis dependence, type 2 diabetes mellitus, Raynaud's phenomenon, CTD, acrocyanosis, erythromelalgia, recent manicure or hand trauma, routine use of vibratory tools, psoriasis, bleeding disorder, or exposure to toluene or benzoyl. NVC was performed at the time of enrollment. A semiquantitative scale calculated by 2 providers was used to score several parameters including enlarged or giant capillaries, hemorrhages, capillary density, disorganization, or ramifications. We compared baseline characteristics and NVC Scores of patients with AAV to non-AAV controls using a Wilcoxon rank sum test for continuous and ordered variables. Fisher's exact test was utilized for categorical variables. <h3>Results</h3> Twenty-four patients with small vessel vasculitis and 13 control patients were enrolled. One patient with cryoglobulinemic vasculitis was excluded. Baseline assessment reported in <b><i>Table 1</i></b>. Patients with AAV tended to be older than the non-AAV controls (median 58 years vs. 40 years). Among patients with AAV, 58% were female, 83% ANCA positive. C-ANCA present in 43%, PR3 in 48%, P-ANCA in 35% and MPO in 35%. Four of the 23 patients (17.4%) had an active flare within 90 days prior to NVC assessment. We did not observe any statistically significant difference in NVC scores between AAV patients and non-AAV controls (all P&gt;0.12, <b><i>Table 2</i></b>, <b><i>Figure 1</i></b>). Some non-specific NVC changes were observed in the AAV group such as ramifications and decreased density which were not observed in the control group though these did not reach statistical significance. <h3>Conclusion</h3> ANCA-associated vasculitis was not strongly associated with NVC abnormalities. Some non-specific changes were observed, and further research may help identify whether these abnormalities correlate with specific disease manifestations or disease activity. <h3>References</h3> [1]Jung P, Trautinger F. Capillaroscopy. J Dtsch Dermatol Ges. 2013;11(8):731-6. [2]Alba MA, Jennette JC, Falk RJ. Pathogenesis of ANCA-Associated Pulmonary Vasculitis. Semin Respir Crit Care Med. 2018;39(4):413-24. [3]Couser WG. Pathogenesis and treatment of glomerulonephritis-an update. J Bras Nefrol. 2016;38(1):107-22. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.